The laser projection display technology has advantages of vivid color, high brightness, low cost and the like. A laser projection display system may be generally divided into three portions, i.e., a laser light source system, an optical-mechanical lighting system, and a lens imaging system.
The laser light source system, as shown in FIG. 1, includes a laser, a fluorescent wheel 2, a lens, and other elements. The basic operation principle is as follows: after blue laser light emitted by a laser is irradiated onto a fluorescent wheel rotating at high speed, primary color light sources required by projection display are generated in timing sequence, and those primary color light sources are passed to the subsequent optical-mechanical lighting system and the lens imaging system to finally generate a colorful picture on the screen.
When in operation, the fluorescent wheel is always rotating at high speed. Due to a too small spacing between a front lens 3 and a rear lens 4 thereof, a wind cutting sound is generated during the rotation of the fluorescent wheel, and noise is thus caused. Furthermore, if the substrate of the fluorescent wheel becomes more out-of-flatness, the axial run-out during the rotation is more severe and the resulting noise is higher.
The machining process of fluorescent wheels is difficult to ensure excellent consistency of flatness of the produced substrates. There are always some fluorescent wheels unqualified in flatness. If such fluorescent wheel is assembled in a laser light source system, the finished machine product will generate high noise due to the out-of-flatness of this fluorescent wheel. Consequently, the finished machine product is unqualified. In order to deliver qualified finished machines, an existing approach is usually to detect noise of finished machines and reject unqualified products having high noise. To do this, it is necessary to establish a dedicated noise detection room where a person is specially assigned to detect noise of finished machines one by one. For those products having high noise rejected upon noise detection, it is necessary to replace their fluorescent wheel components. After the replacement, those products are subjected to noise detection again. This will be repeated until those products are qualified.
Obviously, this approach of rejecting fluorescent wheels unqualified in flatness by detecting noise of finished machines in the prior art increases the complexity of detection and decreases the production efficiency.